Renal Doppler

[Merrin Jackson]

Hi Steve,

A colleague has asked some questions regarding Renal Dopplers.
I have posted my answers but can you let me know your thought also please?

Regards,

Merrin (Perth)

!. Are accessory renal arteries important or not?
From my experience, my theory is that accessory renal arteries only become important if there is a stenosis. occlusion of the main renal artery. I don’t spend much time looking for accessories if they are not obvious when seeing 1 renal artery each side.

2. Should acceleration times be only performed recorded from the renal hilum?
I would think that they could be recorded from anywhere within the kidney.

3. Do RI’s have to be recorded from the arcuate arteries as an indication of the cortical resistance to blood flow?
I was originally taught this when I trained in Vascular with a vascular surgeon, Sydney but on subsequent teachings over the year (I think from 1 of your lectures?) I learnt that RI’s could be taken from anywhere within the kidney/ anywhere where a good signal can be obtained.

An article I found:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3567456/#:~:text=The%20procedure%20begins%20with%20the,abdominal%20wall%20and%20the%20flank.

[Stephen Bird]

Hi Merrin,

1: I do look for accessories and find them easy enough to see on the right side as I look for the renal arteries under the IVC as an isolation plane. On the left I think I miss most of them !

If I find one I try to assess it, especially at the origin.

2: I see people trying to obtain their intra-renal waveforms really peripherally in the renal cortex area and I think this is just making life hard for yourself. I do mine in the interlobar arteries more centrally in the kidney. If you think about it, if there is a stenosis in the renal artery origin that you can not see due to gas etc the acceleration time will be increased at all points distal to the stenosis so you don’t need to be in some tiny peripheral vessel to make the diagnosis. If you go too peripherally the signal to noise ration is poor and the resulting waveform being of poor quality will give you a false positive diagnosis !
3: Also with intra-renal RI the same applies, if the cortex has disease the RI will be increased in the interlobar arteries so again don’t go too peripheral.

Steve

[Merrin Jackson]

Thanks Steve!

[Stephen Bird]

My pleasure Merrin,

Please feel free to use the forum as often as you like,

Steve

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